Year Number 1969 15000 1970 15000 1971 15000 1972 14700 1973 15400 1974 14350 1977 16000 1978 16000 1979 16000 1980 17800 1981 17000 1982 850 1983 1100 1984 1420 1985 1890 1986 1800 1987 1900 1988 2007 1989 2118 1990 1750 1991 1720 1992 1990 1993 2225 1994 2172 1995 1612 1996 1591 1997 290 1998 157 1999 186 2000 130 2001 62 2002 62 2003 62 2004 245 2005 409 2006 716 2007 200904 2008 201160 2009 201310 2010 201544 2011 202013 2012 203635 2013 204331 2014 173591 2015 173745 2016 172047 2017 122804 2018 67283 2019 67749 2020 68089 2021 39328 2022 29341 2023 29336